In the metallurgical or metalworking field, sheets or pieces of a metal or metal alloy are processed in any number of ways that can raise the temperature of the sheet above the temperature of the ambient room temperature. The processed sheets are subsequently rolled into a coil. For example, sheets that have been treated using a cold rolling process can reach temperatures above 200° C. during the process. Heat treatments utilized to treat sheets include, but are not limited to, continuous annealing/solution heat treatment (SHT) and batch annealing. During a continuous annealing/SHT process, the sheet is uncoiled and then first passed through a furnace section and then a quench section. For some metals or alloys, the sheet comes off the quench at higher than room temperature. During batch annealing, the entire coil is placed in a furnace where it is heated to a predetermined temperature and held for a predetermined period of time, such as several hours, after which the coil is removed and allowed to cool.
Following a procedure such as, but not limited to, one of the above described procedures, it is often necessary to cool the sheet coils to ambient room temperature either as a final step prior to storing/shipping or the like, or in preparation for a subsequent step in a manufacturing sequence.
One current practice in the art is to provide forced air cooling by positioning an axial flow fan adjacent a coil and directing air flow at the coil. The air flow is generally perpendicular to the horizontal axis of the coil at the surface of the coil end, and the velocity of air is limited by the air exit velocity of the fan. When the coil has a hollow core or center, some of the air passes through the coil center and therefore does not contribute significantly to coil cooling. Furthermore, some of the air passes along the outside of the coil diameter and also does not provide efficient heat transfer.